Tooth for a Tooth (Di Gilchrist 3)

are worth it.’
    ‘In what way?’
    ‘Less wooden-looking. More lifelike. I could send a digital image tomorrow. That work for you?’
    ‘That works,’ he said.
    Another couple of clicks, a password typed and a string of files with numerical identification that meant nothing to Gilchrist flowed down the screen. She clicked again, and the digital waterfall stopped.
    ‘Let me show you,’ she said, as the image of a human skull appeared on the screen. She jiggled the mouse and the skull turned left, back to the right, rolled over and around and back to face-on again. ‘By holding down the left button and dragging the mouse, you can rotate the image any way you like. Here. Try it.’
    Gilchrist obliged, and the skull span on its spot. He clicked again, managed to stop it, but turned it over so that he was looking at it from above. Another couple of clicks and drags and he had the skull stopped, almost back to where it began.
    ‘Three-D imaging,’ Black said. ‘Helps us develop a more accurate picture. But there’s still a lot of guesswork goes into the final image. Skin tone. Hair colour. Eye colour. Shape of the nose. Lips. Ears. We mostly skip the ears. Each of which leaves a different visual impact on the beholder. Here, let me show you.’ She spun the skull on its spinal axis, returning it to its original position.
    ‘Certain parts of the face we know have little skin covering.’ As she spoke, her fingers worked the mouse. ’Around the eyes, for example.’
    The skull took on a ghostly appearance as the bone around the eye sockets seemed to evaporate and fill in with something that spread down both cheeks like fungus. Then the sockets softened and pooled with the same spectral imagery until a pair of eyes took form.
    The half skull, half face mask caused the hairs on Gilchrist’s neck to stir.
    With a click, the eyes changed from dark to light.
    ‘I’ve got it on greyscale for speed,’ she said. ‘Colour would show these eyes as blue.’ Another click, and the eyes darkened. ‘Green,’ she said, then another click. ‘Or back to brown. Of course, we have no way of telling if the eyes are heavy-lidded, hooded, wide open or narrow. What we can do is give a best-guess estimate of what the face should look like. Sometimes it’s best to play the odds.’ Another click, and the eyes shut.
    Gilchrist watched in silence as Black worked the mouse, filling in the remainder of the skull until he was left looking at a bald head that rotated and rolled before him as if Black was showing off her finished sculpture. Gilchrist puzzled that it looked oddly familiar.
    Black turned the skull to profile and placed the cursor on the nose. ‘This,’ she said, ‘in my opinion, is the most difficult feature to portray with any real accuracy. The nose is shaped with cartilage that can deform over the years. Accidents, fights, even the simple act of sticking a finger into the nasal cavity over a period of time can deform the cartilage.’ She dragged the mouse over the nose, creating a bulge on the bridge and turned the skull face-on. Another couple of clicks and the nose widened. ‘Different. Don’t you think?’
    She repeated the exercise, this time giving the nose a delicate concave curve.
    Straight on again, the bald head had a more refined look to it. Gilchrist studied it. ‘Seems familiar,’ he said.
    Black smiled. ‘Would you like me to add glasses?’
    Gilchrist almost gasped. He turned to Black, back to the skull, then Black again.
    ‘That’s you?’ he asked.
    She nodded. ‘Without the telltale markers of hairstyle, colour, glasses, the memory isn’t triggered by any recognizable feature. There’s nothing locked in memory for the brain to pull up. So it sees the image as a stranger.’ She worked the mouse again, until a woman’s face with blonde spiked hair rotated on the screen. ‘That’s what I would look like as a punk rocker.’ She added nose and ear piercings, and chuckled. ‘Not so stunning. Right?’
    ‘Right,’ he agreed.
    The blonde spikes melted and shifted to shoulder length. ‘How about that?’
    ‘I think I’m used to you not being blonde.’
    Another click, and the hair faded to light grey. ‘Better?’
    ‘Getting there.’
    She clicked the mouse. The skull vanished. ‘That,’ she said, ‘is what I mean by guesswork.’
    ‘Still,’ he said, ‘it’s all we have to go on.’
    She nodded. ‘We have the sceptics in the profession, of course. The die-hards, the